Digital Subtraction Angiography (DSA) is a known process employed in angiography imaging applications in radiology to remove background anatomical data which distracts from clinically relevant vessel structure of a patient. For example, in neuro-radiological imaging studies, a physician may desire to see the vessel structure of a patient brain without being obscured by the boney structure of the skull. In performing a DSA process, a single mask frame (containing background anatomical detail for removal from images) is selected from a scene and subtracted from the image frames. FIG. 1 illustrates subtraction of Mask image data 107 from corresponding Fill image data 105 to provide desired DSA image data 103.
A Mask image frame is typically selected by a known laboratory information system in response to a determination that a regulated patient dose of the x-ray field has been completed. The Mask image frame in known systems is selected in a virtually arbitrary fashion based upon laboratory conditions irrespective of image quality and may often be less than optimal, resulting in the burden of selection of a new Mask image frame. The selection of a new Mask image frame is typically performed in a post-processing operation, when a patient procedure has already been completed and the patient is no longer present. Therefore, in known systems the enhanced image quality provided by new and more accurate Mask image selection occurs too late to improve guidance to a physician performing a radiological procedure on a patient. A system according to invention principles addresses these deficiencies and related problems.